<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    .c1{
      background-color: red;
      height: 200px;
      width: 200px;
      /*display: none;*/
    }
  </style>
</head>
<body>

<div class="c1"></div>

<ul>
  <li>11</li>
  <li>22</li>
  <li>33</li>
  <li>44</li>
</ul>

<script src="jquery.js"></script>

</body>
</html>